Fixing apparatus for thermoplastic recording

ABSTRACT

A vertical type fixing apparatus for thermoplastic powder recording comprising a transport means for support on which thermoplastic image patterns are deposited, a heating means for rapidly and permanently fixing the thermoplastic image patterns on the support, a blower means for circulating rising heated air, and a guide means for promoting air circulation.

United States Patent Obuchi et a1.

FIXING APPARATUS FOR THERMOPLASTIC RECORDING Inventors: Kazuo Obuchi;Koichi Takiguchi,

both of Odawara, Japan Assignee: Fuji Photo Film Co., Ltd.,

Kanagawa, Japan Filed: Mar. 13, 1972 Appl. NO.I 233,932

Foreign Application Priority Data Mar. 11, 1971 Japan 46-13342 US. Cl432/230, 432/59, 219/216 Int. Cl G03g 8/00 8 Field of Search 263/6E;'95/13, 14, 94;

References Cited UNITED STATES PATENTS 7/1973 Peek, Jr. eta1 432/45 1Apr. 23, 1974 3,492,458 l/l970 White et al. 34/10 3,145,637 8/1964Frantz 95/94 3,448,970 6/1969 Kolibas 432/62 3,700,218 10/1972 Laisney432/62 3,498,592 3/1970 Moser et al..... 432/62 2,664,282 12/1953 Mann432/42 Primary Examiner-John J. Camby Assistant Examiner-Henry C. YuenAttorney, Agent, or Firm-Sughrue, Rothwell, Mion, Zinn and Macpeak [57]ABSTRACT A vertical type fixing apparatus for thermoplastic powderrecording comprising a transport means for support on whichthermoplastic image patterns are deposited, a heating means for rapidlyand permanently fixing the thermoplastic image patterns on the sup port,a blower means for circulating rising heated air, and a guide means forpromoting air circulation.

4 Claims, 1 Drawing Figure FIXING APPARATUS FOR THERMOPLASTIC RECORDINGBACKGROUND OF THE INVENTION I 1. Field of the Invention The presentinvention relates to an apparatus for fixing thermoplastic powder imagepatterns deposited on the surface of a support material. Moreparticularly the present invention relates to a vertical type fixingapparatus in which thermoplastic powder image patterns formed loosely onthe support such as, for example, a xerographic plate or anelectrostatic recording or duplicating paper are fixed permanently onthe support by heating.

In this disclosure, the term vertical type" fixing apparatus denotes anapparatus for fixing in which the support for the thermoplastic powderimage patterns is transported vertically and one or a plurality ofheating elements are provided parallel with the support to accomplishthe fixing by heating.

2. Description of the Prior Art Heretofore, in the case ofelectrophotography or similar techniques, the so-called horizontal typefixing apparatus in which the support is transported horizontally andheating elements are provided in parallel with the carrier path toaccomplish the fixing of the thermoplas tic powder image patterns formedon the carrier has been widely used. The reason the horizontal typefixing apparatus has been widely used, while the vertical type fixingapparatus has not been utilized as much, is as follows: Certainundesirable disadvantages and limitations of the vertical type fixingapparatus are known and these include a temperature reduction on theinside of the fixing apparatus and a temperature increase on the insideof the duplicating machine and similar problems due to the fact that, inthe case of vertical type apparatus, relatively cold air is suppliedfrom below and air heated by the heating elements flows upwardly. Thatis, the temperature reduction on the inside of the fixing apparatusrequires that much more electric power be supplied to the heatingelements to accomplish the fixing of the thermoplastic powder imagepattern on the support, and the temperature increase in the machine maycause adverse effects on the photoconductive layer or malfunctions ofand difficulties with the electrical equipment.

SUMMARY OF THE INVENTION It is, therefore, an object of the presentinvention to provide a novel and improved vertical type fixing apparatusfor thermoplastic recording It is another object of the invention toprovide a vertical type fixing apparatus which is so arranged that theelectric power consumption in the apparatus is reduced to a greatdegree, and that the heat in the apparatus is prevented from flowingoutwards resulting in an avoiding of a temperature increase in theinside of the machine suchas a duplicating machine.

To accomplish these objects, the present invention provides a blowermeans and guide means having the function of circulating the heated airand downwardly returning the heated air rising from the heatingelements.

Other objects of the invention, as well as other advantages and featuresthereof, will become apparent and be better understood from a furtherreading of the following disclosure of an embodiment of the inventiontaken in conjunction with the appended drawing.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWING The FIGURE depictsschematically an arrangement of the fixing apparatus in accordance withthis invention.

0 DESCRIPTION OF PREFERRED EMBODIMENTS As shown in the FIGURE, thefixing apparatus is provided with a heating means 1 which consist ofheating elements such as, for example, tubular infrared lamps ornichrome wires. The heating means 1 includes sufficient numbers ofheating elements so as to supply the quantity of heat required to fixthe thermoplastic powder image pattern on the support. Reference numeral2 denotes a reflector for the heat radiated from said heating means 1.Reference numeral 3 denotes a circulating fan as a blower means being amain part of this invention, which rotates in the direction of the arrowto return downwardly the rising heated air. Numeral 4 indicates aninternal cover for guiding the air current which is of such shape thatthe air circulation due to the rotation of the circulating fan 3 ispromoted efficiently thereby. Numeral 5 denotes an outside cover.Reference numeral 6 denotes a exhaust fan secured to the upper part ofthe outside cover 5 for exhausting outwardly the remaining portion ofthe rising heated air which could not be recirculated downwardly by thecirculating fan 3. Reference numeral 7 indicates a shutter which, duringthe preheating period of heating elements 1 or in an unexpected powerstoppage, drops to the dotted lined position 8 so as to reduce the timerequired in preheating or to prevent the support from scorching orcatching fire. Reference numeral 9 denotes a support for thermoplasticrecording, such as, for example, a web or sheet which may be transportedin a plane parallel with the direction of the heating elements disposedvertically. Numeral 10 denotes an unfixed thermoplastic powder imagepattern on the support 9, while numeral 11 denotes the image patternfixed on the support 9 after passing through the fixing apparatus.

Furthermore, in the left side of the apparatus (not illustrated), imagepatterns of a thermoplastic powder are deposited on the roll papercarrier using an electrophotographic process. Reference numerals 12 and13 denote guide rollers for guiding the vertical transport of thesupport 9, and both ends of the support are connected to a supplyreeldevice and take-up reel device (not shown) respectively. Referencenumeral 14 denotes a adiabatic plate for preventing the transmission ofheat through the support paper 9 to the exposure device and/ordeveloping device positioned in the left side of the FIGURE (not shown).

The operation of the fixing apparatus arranged in the manner describedabove will be now explained in greater detail hereinafter.

First, during preheating period, the shutter 7 is in the down position 8forming a thermal seal for the heating elements 1 with the reflectingplate 2 so that the shutter 7 prevents the transmission of the heat tothe support 9 and the heating elements 1 themselves are heatedefficiently thus reducing the time for preheating. Just after theheating elements 1 are heated sufficiently to permit fixing, the shuttermoves up to the position 7 and, at the same time, transport of thesupport 9 is begun. Thus the cycle of operation of the fixing forthermoplastic recording or duplicating starts. The air heated by theheating elements 1 rises along the support 9 and is taken in by thecirculating fan 3 rotating in the direction of the arrow, essentiallywithout leakage. The absorbed hot air is guided passed through the backside of the reflecting plate 2 inside of the internal cover 4 to anopening formed between the lower end of the reflecting plate 2 and thatof the internal cover 4, and the air is blown therefrom onto the support9 at an angle perpendicular to the support. The temperature of thecirculating air may be increased by coming into contactwith thereflecting plate 2 while passing through the inside of the internalcover 4. Thus, it will be apparent that the heated hot air is blowndirectly onto the carrier on which thermoplastic powder image patternsare deposited with a high fixing efficiency and accordingly the electricpower to be applied to the heating elements may be reduced. The blownair current is heated by the heating elements and rises to be absorbedby the circulating fan again thus, the air circulating process mayberepeated during the operation in which thermoplastic recording orduplieating is performed.

THe circulation of the heated air current prevents the inflow ofrelatively cold air from the outside into the apparatus resulting inavoiding a reduction of temperature in the fixing apparatus with littleleakage of heat. Even a small quantity of air which might leak into therecording or duplicating apparatus would be exhausted out immediatelywithout any temperature increase in the recording or duplicatingapparatus.

After the recording or duplicating operation is finished the powersupplied to the heating elements is switched off, and at the same timethe shutter drops down to the position 8 and transport of the support isstopped.

The fixing apparatus of the present invention as described above hasbeen operated and compared with that of prior art. The results obtainedare as follows:

Experiments have been made for the following three,

cases: (i) a fixing operation of the vertical type fixing apparatus withthe circulating fan being rotated, (ii) fixing operation of the verticaltype fixing apparatus without the circulating fan being rotated, (iii) afixing operation of the horizontal type fixing apparatus with heatingelements disposed horizontally. The power consumption required toaccomplish the rapid fixing of the image patterns of thermoplasticpowder on the support was measured in the three respective cases underthe following conditions: 2KW of electric power was applied forpreheating for l minute. The speed of the support transport was 10.2cm/sec. The width of the support paper was 30 cm, and a 1.5 cm gap wasset between the surface of the support paper and the heating elements. Athermoplastic powder of the type commercially available as 914/420 TONERfrom Fuji Xerox Company was used.

The measured power consumption which fixed the thermoplastic powderimage pattern perfectly on the support was (i) 1.0 KW in the verticaltype apparatus with rotating the circulating fan, (ii) 1.35 KW in thevertical type apparatus without rotating the circulating fan, and (iii)1.2 KW in the horizontal type apparatus.

The circulating fan used in .the experiment of the vertical typeapparatus had a diameter of 10cm. and a rotating speed of 800 rpm. andthe heated air current jetted from the opening 15 in the FIGURE at atemperature of 200C and a flow rate of 2m/sec.

From the above described results of the experiments,

to a considerably high temperature (for example,

200C in the embodiment described above), they should be heat-resistantto such high temperatures.

While the present invention has been described with reference to aspecific embodiment, it is to be understood that the embodimentdescribed is only for the purposes of illustration and variousmodifications and changes may be made in the present invention withoutdeparting from the spirit and the scope of the invention as definedherein and by the appended claims.

What is claimed is:

1..A heat-fixing apparatus for thermoplastic powder recording orduplicating comprising a 1. transport means for vertically transportinga support carrying image patterns of a thermoplastic powder,

2. one or a plurality of heating elements disposed in parallel with thetransport path of said support,

3. blower means for collecting heated air as it rises from areasadjacent said heating elements and downwardly returning said heated aironto the surface of said support in an area of said support below saidheating elements,

4. guide means for promoting the circulation of the air, 5. a reflectingplate at the side of said heating elements opposite to said supporttransport path, and

6. a shutter movably mounted between said support and said heatingelements, whereby heat supplied to said support from said heatingelements can be discontinued when the fixing operation is not practiced.

2. A heat-fixing apparatus for thermoplastic powder recording orduplicating as set forth in claim 1 wherein said transport meanstransports said support downwardly, whereby an ascending current ofheated air from said heating elements warms said support prior to saidblower means comprises a circulating fan.

1. A heat-fixing apparatus for thermoplastic powder recording orduplicating comprising a
 1. transport means for vertically transportinga support carrying image patterns of a thermoplastic powder,
 2. one or aplurality of heating elements disposed in parallel with the transportpath of said support,
 3. blower means for collecting heated air as itrises from areas adjacent said heating elements and downwardly returningsaid heated air onto the surface of said support in an area of saidsupport below said heating elements,
 4. guide means for promoting thecirculation of the air,
 5. a reflecting plate at the side of saidheating elements opposite to said support transport path, and
 6. ashutter movably mounted between said support and said heating elements,whereby heat supplied to said support from said heating elements can bediscontinued when the fixing operation is not practiced.
 2. Aheat-fixing apparatus for thermoplastic powder recording or duplicatingas set forth in claim 1 wherein said transport means transports saidsupport downwardly, whereby an ascending current of heated air from saidheating elements warms said support prior to fusing of the thermoplasticpowder.
 2. one or a plurality of heating elements disposed in parallelwith the transport path of said support,
 3. blower means for collectingheated air as it rises from areas adjacent said heating elements anddownwardly returning said heated air onto the surface of said support inan area of said support below said heating elements,
 3. A heat-fixingapparatus for thermoplastic powder recording or duplicating as set forthin claim 1 further comprising exhaust means located upwardly of saidblower means for exhausting from the apparatus that portion of heatedair which is not recirculated downwardly by said blower means.
 4. Aheat-fixing apparatus for thermoplastic powder recording or duplicatingas set forth in claim 1 wherein said blower means comprises acirculating fan.
 4. guide means for promoting the circulation of theair,
 5. a reflecting plate at the side of said heating elements oppositeto said support transport path, and
 6. a shutter movably mounted betweensaid support and said heating elements, whereby heat supplied to saidsupport from said heating elements can be discontinued when the fixingoperation is not practiced.